This invention relates to display devices and in particular to localized control of brightness level in a video display apparatus of the type utilized with a computer or the like.
A video display device such as a cathode ray tube (CRT) is frequently utilized as a display in conjunction with data processing apparatus such as computers, word processing systems or the like. Heretofore, such systems have usually produced a display of uniform brightness upon the associated video display apparatus. For example, alphanumeric characters are generally displayed as a collection or pattern of illuminated points or pixels on the video screen. However, the brightness of all of these points or pixels making up these alphanumeric characters has heretofore been uniform.
While the overall brightness level of such displays may often be controlled by the operator, many systems have not made any provision for emphasizing given characters or patterns. In many applications, the operator may wish to verify or identify certain information which may be contained in the display, without the necessity of visually inspecting the entire display. Hence, some method and apparatus for emphasizing or highlighting the desired information might prove particularly useful in such applications.